Liquid-fuel burner



Nov. 22, 1927. 1,650,391

E. J. Y. RUTHERFORD LIQUID FUEL BURNER Filed Avril 10. 1925 2 Sheets-Sheet 1 I Z 5 I "mi" hi 11 h Nov. 22, 1927. 1,650,391

E. J. Y. RUTHERFORD LIQUID FUEL BURNER Filed April 10. 1925 2 Sheets-Shea. 2

i wwvW- Patented N0 22, 1927.

UNITED STATES EDWARD JAMES YOUNG RUTHERFORD, OF CHELTENHAM, ENGLAND.

LIQUID-FUEL BURNER.

Application filed April 10, 1925, Serial No. 22,157, and in Great Britain April 12, 1924.

. This invention relates to liquid fuel burners of the type in which the fuel is atomized by a jet of steam generated in a flash boiler heated by the flame of the burner.

The present invention consists primarily in an improved arrangement and construction of the burner and of the steam genera tor and has for its main object to allow the use of cores, for example solid rods or flexible wires within the tubes of the steam generator in order to restrict the contained fluid to the annular passages around such cores; the cores may extend. throughout the length of the tubes or for that part of their length in which the water is assumed to remain in the liquid state. The invention also comprises an improved arrangement of the burner-accessories with a view more particularly to the installation of comparatively large apparatus.

The lnvention has also for its object to provide for interlocking the parts of the apparatus, to obviate risk of improper operation, especially when changing over from the preliminary heating by compressed air to the normal running with steam atomization.

The invention is hereafter described with reference to the accompanying drawings, in which z- Figure 1 is a sectional elevation of one form of burner with tubular generator for the fuel atomizing steam.

Figure 2 is an end view from the rear of the burner, the guard being removed. 7

Figure 3 shows the fuel-nozzle and its supporting tube, detached from the burner, and drawn to a larger scale.

Figure 4 is an end view of the hollow cappiece which forms the junction for the generator tubes.

Figure 5 is a diagram of an oil-burning installation, illustrating the arrangement of the accessories.

Figures 6 and 7 represent the burner provided with a suitable form of interlocking trip device for controlling the oil supply.

Referring to Figures 1 to l, the" burner I comprises a steam generator formed by four straight tubes a a a a secured at one end in the base of a. hollow cap-piece a, so as to diverge at equal angles. to the axis of the burner; as shown the holes bored in the cappiece to receive the tubes intersect so as to afford an intercommunication chamber a wherebythe parallel paths for the fluid passing through the tubes are cross-connected at this point. Two opposite tubes a a are connected at their other ends to the extremitiesof a hollow cross bar I) from the centre of which there projects in the line ofthe axis a steam-discharge nozzle 0 directed to wards the cap-piece a; on the opposite side of the bar I) there is-fitted a screw-plug d with a knob or handle al and a pricker. rod or needle (Z for clearing the nozzle 0.

The extremities of the cross bar I) which receive these two tubes a a are provided on the opposing faces with apertures 6 aligned with the bores of the tubes, and normally closed by cap nuts I), through which apertures there may be introduced a pair of rods 6 e adapted to form cores for the tubes a a these rods being held in central relation to the tubes by said apertures. The other endsof the rods extend freely into the intercommunication chamber a in the cappiece a.

The free ends of the other pair of tubes a a are connected to socket pieces f. also provided with apertures similar to 6 for the introduction of central core-rods e e,

these apertures being normally closed by cap nuts f these two socket pieces are connected together by a semi-circular or other pipe g, to the central point of which the feed-water is led by a pipe 9 The burner is preferably fitted with a convergent-divergent deflector i wedged upon the tubes a a 00 0*, and with a guard j at the rear end, this guard being of cupshape with a central hollow boss 3' which fits around the pricker device d d 61 with out obstructing access to the latter.

The liquid fuel nozzle h is preferably arranged to one side of the steam nozzle 0, being supported by a tube 7L mounted in a lug k upon the cross-bar b, the position being such that the fuel nozzle is directed towards the axis of the steam nozzle and lies preferably equidistantly between two adjacent legs or tubes of the generator; the axis of the fuel nozzle may be inclined obliquely, atan angle of'eighty-five degrees for example, to the axis of the steam nozzle 0, as illustrated in Figure 3.

The fuel flows from this nozzle h, either under suction or under pressure or gravity,

according for example to the nature of the fuel or the size of the burner.

The steam nozzle may comprise a central orifice c and an enlarged mouth 0 both aligned with the axis, and a number of airholes 0 passing through the walls at the inner end of the mouth, the pricker rod d being adapted to enter the central orifice 0 when theplug (Z is screwed into its seating.

Thus the water is led by symmetrical paths to the socket-fitted ends of one pair of tubes a a*, passing along the annular spaces around the cores 6 e in the same, towards the hollow cappiece a, being ex posed in its travel to the heat of the flame produced by the atomized fuel. Upon reaching the intercommunication chamber a in the cap-piece a, the two streams of water unite and then divide between the other two tubes a along which the fluid returns towards the hollow cross-bar Z2, still passing through the annular spaces around the cores 6 e The eliect of the presence of these cores 6 e c e is to reduce the water to an annular stream, incidentally giving an increased etficiency as regards the heating surface, but chiefly intended to prevent the stream from being broken, and thus to ensure a constant flow without any tendency to surging; in this way the generation and the discharge of steam are rendered uniform, and the suction and the atomization of the fuel are in turn made regular, resulting in a very steady flame from the burner at all out-puts.

The cores or rods 6 e e 0 need not we tend throughout the length of the tubes a a a a it being sufficient to provide cores in the parts where the water is still in the liquid state; nevertheless, for practical convenience the cores may be continued through the entire straight portions of the tubes.

Vhen fitting the cores, one rod may be cut of sutlicient length to reach the bottom of the corresponding hole a in the cap piece a, and the other rods cut to shorter lengths, being wedged in position in the outer parts ofthe respective holes in the cap-piece.

In applying the improved burner to an installation, such as a central heating plant, as represented in Figure 5, I provide a suitable vessel C for containing air and water, the air beng supplied for example by a hand pump D and the water through a shutoff cock A from a service main under suitable pressure. The admission of water to the vessel is controlled automatically by a valve B operated by a diaphragm exposed to the air pressure from the vessel 0, so that the water is shut oli at a given compression of the air; the internal pressure in the vessel is thus maintained approximately constant, more water being admitted to replace that discharge, and also it necessary to replace the air.

There may also be provided a water sottener E with chemical supply tank E of any suitable type for treating the water in its passage to t is burner, in order to'reduce deposits in the generator; valves F and F are arranged in the pipe line to allow of cutting out the water softener.

The water passes from the softener E, or direct from the vessel O, through a valve G to the steam generator I. r

The air from the upper part of the vessel C is supplied through a regulating valve H to the steam generator I of the oil burner, in such a way that the burner can be started up on the compresed air.

The air pressure may also be employed to control an automatic valve 0 in the pipe R supplying the oil from its reservoir N, so that it the air or water pressure fails, the oil supply will be cut off. In passing towards the burner, the oil may be heated to reduce its viscosity, for example it may be led through aheating drum L containing-a steam coil L which is supplied for example trom a separate steam-generating coil K heated by the burner, as shown, the water supply to this coil being regulated by a valve J. It desired, an electric or other heating device Q, may be provided for preheating the oil when steam is not available.

The oil supply is preferably also'controlled by a trip valve actuated by a thermostat, which is arranged to cut oi? the oil in the event of the flame being extinguished or if its temperature falls below a predetermined point; means are provided for holdingthis valve open at starting until the thermostat comes into operation. As illustrated in Figures 6 and 7, the trip-valve 7c, arranged in line with the tube 7L1 supporting the fuel nozzle, comprises a sliding plug actuated by a spring k and tending to close the passage into the tube M. The head 70 0f the plug is enga ed by the toe Z of a lever Z pivoted on the a. lug Z on the side of the bar Z; and maintained in the engaged position by a spring Z; the other end Z of the lever bears against a thermostatic device, which in the example shown consists of the core 6 of the generator tube a this core rod 6 projecting through a stufiing box which replaces the ca -nut 79 shown in Figure 1. By makim b the core rod of a non-expansible metal, such as a. suitable nickel-steel alloy, the contraction of the generator tube on cooling may be utilized to produce relative movement of the rear end of the core, thus releasing the valve plug 7& and cutting oil the supply of fuel it the flame is extinguished. The same or a similar thermostat may actuate a valve such as G (Figure 5) in the water. supply, to turn on the water when the burner reaches its working temperature and to cut off the water 7 simultaneously with the oil, when the temperature falls. The valve plug can be held up in the open position for starting from cold, by the engagement of a trip lever on with the head of the plug.

To ensure that the trip valve In in the oil supply is properly set at starting, it is preferably interlocked with the air-regulating valve H, so that the latter cannot be closed to leave the generator in its normal condition, that is, running on water, until the trip-lever m has been released so that the thermostat is in control of the oil supply through the trip valve it". Thus at starting, the thermostati- Cally-controlled trip valve for the oil supply will beheld open by the trip lever 122., while air is admitted through its regulating valve H. After the heating of the burner and generator by initial running on air, the expansion of the generator tube (1- produces a relative movement of the core 6 allowing the lever Z to be engaged with the head k of the plug M; the trip lever m is then released to place the thermostat in control of the valve k, this release being effected automatically prior to the closing of the air-regulating valve. For example the spindle of the air-valve may be fitted with a cam or eccentrio m adapted to engage the lower end m of the trip lever m as the air-valve is screwed down.

The invention is not limited to the particular arrangements mentioned nor to the details of construction given by way of example; the generator tubes may be slightly curved or bent and the cores made of flexible wire. These and other parts of the burner may with advantage be made of non-rusting and non-corroding materials.

Having thus described my invention, what I claim is 1. A liquid fuel burner of the steam atomizer type, comprising a plurality of steam generator tubes heated by the flame of the burner, said tubes being disposed in two sets of substantially equal length and dimensions, said sets of tubes affording alternative paths for water fluid, cores fitted within said tubes, said cores limiting the passage area for the water, and means for obtaining access to said cores at points outside the flame zone of the burner.

2. A liquid fuel burner of the steam atomizer type, comprising a plurality of convergent steam generator tubes heated by the flame of the burner, the axis of said tubes intersecting substantially upon the axes of the burner, and cores fitted within said tubes, said cores being removable at the ends of said tubes remote from the point of intersection.

3. A liquid fuel burner of the steam atomizer type, comprising an even number of straight steam generator tubes heated by the flame of the burner, said tubes arranged therethrough.

'tion between each pair of tubes, means for supplying water to the diverging ends of alternately spaced tubes, cores fitted within said alternately spaced tubes, said cores supported by said hollow member at one end, means for delivering steam from the diverging ends of the remaining tubes, the path for water and steam through each pain of intercon'imunicating tubes being of equal length and sectional area. a steam nozzle, and a fuel suction nozzle disposed in front of said steam nozzle, the axis of said steam nozzle approaching the axis of said fuel n0z-' zle at anangle of about degrees.

4. A liquid fuel burner of the steam atomizer type, comprising pairs of convergent steam generator tubes heat-ed by the flame of said burner, the axes'of all said tubes intersecting substantially upon the axis of the burner, and a hollow member secured upon the ends of said tubes adjacent to the point ofv intersection, said hollow member afl'ording intercommunication between said tubes.

5. A liquid fuel burner of the steam atomizer-type, comprising four convergent steam generator tubes heated by the flame of the burner, means for the supply of water to the divergent ends of two opposite tubes, cores within said two opposite tubes, means for the delivery of steam from the divergent ends of the other two tubes, and a hollow member affording intercommunication between each pair of said tubes at their converging ends.

6. A liquid fuel burner of the steam atomizer type, comprising a plurality of convergent steam generator tubes heated by the flame of the burner, the axes of said tubes intersecting substantially upon the axis of said burner, cores fitted within said tubes, and a hollow cap-piece secured to said tubes at their point of intersection, said cap-piece supporting the ends of said cores and affording communication between said tubes, said tubes and cap-piece providing two equal and alternative paths for water fluid passing 7. A liquid fuel burner of the steam atomizer type, comprising a plurality of tubes arranged in pyramidal form to be heated by the flame of the burner. a cap-piece occupying the apex of the pyramid and affording intercommunication between the adjacent extremities of said tubes, certain of said tubes having their other extremities connected to the water supply, cores within said last mentioned tubes, a hollow member. the remaining tubes having their other extremities connected to said hollow member, and a nozzle mounted in said hollow member, said nozzle delivering steam along the axis of the burner.

8. A liquid fuel burner of the steam atomizer type, comprising a plurality of tubes arranged in pyramidal form to be heated by the flame of the burner, a cap-piece occupying the apex of the pyramid and affording iiitercommunication between the adjacent extremities of said tubes, certain of said tubes having their other extremities connected to the Water supply, cores within said last mentioned tubes, a hollow member, the remaining tubes having their other extremities connected to said hollow member, and a nozzle mounted in said hollow member, said steam nozzle delivering along the axis of the burner, a lug upon said hollow member, and a fuel nozzle mounted in said lug, said steam nozzle and said fuel nozzle having their axes intersecting at an angle of about 85. I 7

9. A liquid fuel burner of the steam atomizer type, comprising a plurality of convergent steam generator tub-es arranged in pyramidal form to be heated by the burner flame, a hollow member located on the axis of the burner, the converging ends of said tubes joining within said hollow member,

cores titted within said tubes, means for supplying water to and delivering steam from the diverging ends of alternatively disposed tubes, and means for the insertion and extraction of said cores, said insertion and extraction means including openings remote from the flame zone.

In testimony whereof I have hereunto affixed my signature.

EDWARD JAMES YOUNG RUTHERFORD. 

